I have a 2007 ES350 with 38k mi. Bought it in Jan 2020 with 32k mi. The car has conventional oil. I'm going to be putting a lot of miles this year, should I switch to synthetic, or keep it with the conventional oil?

 

Congrats on finding such a low mileage vehicle and welcome to CL. . Switch to synthetic oil.. It provides more protection over conventional especially if doing the Lexus recommended 10,000-mile oil change interval. If you are changing it every 5,000 miles then regular oil is fine. If you are paying a shop the price difference is far greater than if doing your own oil changes.

If it has the original coolant I would change it as Lexus calls it 10 year or 100,000 mile coolant.

would also do a few transmission fluid drain and fills or a fluid exchange. Call a few Toyota and Lexus dealers for pricing. Some will do a transmission service and some will refuse.

Same with the brake fluid. It should be flushed every 3 years as it absorbs water which can corrode the ABS and EBD which are very expensive.

Same again with the power steering fluid, although it is almost as good to use a Turkey baster, pull the fluid out of the reservoir and fill it back up with fresh power steering fluid. Then repeat about 4 times over the next week while driving in between to mix up the fluid. The entire system holds less very little and you only need about a quart or 2 to do this.

Since the car is 13 years old, it is just good insurance to change all these fluids especially on such a low mileage vehicle.

2 years ago when my mother quit driving she gave her grandaughter her low mileage 2010 ES350 (44,000 miles) and we changed all those fluids at the local Toyota dealer for around $500.

 

M1 5W30 EP or AP
TGMO 5W30
OEM filter
10000 miles.

 

I do 5w30EP every 5K miles because my wife drives around 7K miles a year, mostly city

 

You can go 1 year between the OCI.

 

Owners' manual recommends 5,000 mile OCI and the previous owner followed that religiously so I'm gonna continue that trend with conventional oil.

Otherwise I like to stick to about 6,000-8,000 with Full Synthetic. Even if the oil can go longer, I prefer to have a spotless engine with a gold finish on all the internals.

Asking about conventional vs synthetic is like talking about Coke vs Pepsi. Do whatever makes you happy and change it regularly.

 

Oil is cheap, especially when DIY. Dont care about getting maximum OCI

 

I've been doing 10,000 mile oil changes with full synthetic. It's awesome.

 

That's what I did for the
last 70000 miles.

 

Our 07 ES350 is approaching 250K. As soon as the warranty expired, I switched to full synthetic 5/30. But, our engine has the timing cover seepage issue. To reduce the seepage, I switched to 10/30 full synthetic at about 120K. Seepage has been significantly reduce and engine is running as expected. Doing 10K intervals, supported by a couple of oil samples I've submitted for analysis; there is a thread here for those.